If you have some patience I can try to do it tonight after dinner (it's 6:08 pm here now).
Here it is:
Place your default avatars in a subdirectory of your home directory named "default_avatars".
I have tested it with a .jpg avatar, if you use .png or .gif files change this at the end of line 25.
The avatars must have exactly the name as you described, for instance for a user with a name starting with an "n" the avatar name must be "image of N alphabet.jpg" (or another extension). Note that the n is capitalized to N!!!
I tested it and it works.
Here it is:
<?php
if(!defined("IN_MYBB"))
{
die("Direct initialization of this file is not allowed.<br /><br />Please make sure IN_MYBB is defined.");
}
$plugins->add_hook("member_do_register_end", "default_avatar");
function default_avatar_info()
{
global $lang;
return Array(
'name' => "default avatar",
'description' => "assigns a default avatar at registration depending on 1st letter of username",
'website' => '',
'author' => 'Ad Bakker',
'authorsite' => '',
'version' => '1.0',
'guid' => '',
'compatibility' => '18*',
);
}
function default_avatar()
{
global $user_info, $db;
$file = "./default_avatars/image of ".strtoupper(substr($user_info['username'],0,1))." alphabet.jpg";
if (!file_exists($file)) return;
$size = getimagesize($file);
$avatar_array = array(
'avatar' => "{$file}",
'avatardimensions' => "{$size[0]}|{$size[1]}",
'avatartype' => "remote");
$db->update_query("users", $avatar_array, "username = \"{$user_info['username']}\"");
}
?>
Place your default avatars in a subdirectory of your home directory named "default_avatars".
I have tested it with a .jpg avatar, if you use .png or .gif files change this at the end of line 25.
The avatars must have exactly the name as you described, for instance for a user with a name starting with an "n" the avatar name must be "image of N alphabet.jpg" (or another extension). Note that the n is capitalized to N!!!
I tested it and it works.

Regards, Ad Bakker (NL)